Side sill for vehicles

Abstract

To provide a side sill that achieves improved efficiency in collision energy absorption and weight reduction.SOLUTION: The present invention provides a side sill (100) for vehicles including a side sill frame (110) that has a hollow part (113), and a reinforcement frame (120) disposed in the lengthwise direction of the side sill frame (110) inside the hollow part (113). The reinforcement frame (120) has unit sections which are continuous in the lengthwise direction of the side sill frame (110) and have varying heights. Upper surfaces and lower surfaces of the unit sections are separated from the side sill frame (110).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vehicle side sill.

Background Art

[0002] The content described in this part merely provides background information for the present invention and does not constitute the prior art.

[0003] A vehicle side sill plays a role in absorbing collision energy during a side collision to protect passengers.

[0004] A side sill applied to an environmentally friendly vehicle such as an electric vehicle also plays a role in protecting not only passengers but also a battery located on the floor surface. Since the battery is relatively large in volume compared to other components of the vehicle, the side space of a vehicle equipped with a battery is relatively narrow compared to a vehicle equipped with an internal combustion engine.

[0005] Therefore, a side sill applied to an environmentally friendly vehicle must be able to absorb the maximum amount of collision energy in a narrow space and must have a minimum weight in order to improve the energy efficiency of the environmentally friendly vehicle.

[0006] For this reason, aluminum extrusion materials have been applied to the side sills of environmentally friendly vehicles, but there is still a continuous demand for improving the collision energy absorption ability and achieving weight reduction.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] One object of the present invention is to improve the collision energy absorption efficiency of a side sill and achieve weight reduction.

[0009] One object of the present invention is to increase the rigidity of a side sill and reduce manufacturing costs.

Means for Solving the Problems

[0010] As one aspect for achieving the above object, the present invention includes a side sill frame including a hollow portion; and a reinforcing frame disposed in the length direction of the side sill frame inside the hollow portion, wherein the reinforcing frame is continuous in the length direction of the side sill frame and has unit intervals in which the height changes, and provides a vehicle side sill in which the upper surface and the lower surface are separated from the side sill frame.

[0011] The unit interval may include a first flat portion positioned parallel to the length direction of the side sill frame; an inclined portion connected to the first flat portion and disposed obliquely; and a second flat portion connected to the inclined portion and existing at a position lower than the first flat portion.

[0012] The inclined portion may include a first inclined portion connected from the first flat portion to the second flat portion and disposed obliquely downward; and a second inclined portion connected from the second flat portion to the first flat portion and disposed obliquely upward.

[0013] A first side sill frame to which one side of the reinforcing frame is joined; and a second side sill frame to which the other side of the reinforcing frame is joined and which is joined to the first side sill frame, wherein the first flat portion and the second flat portion can be arranged to face the joint portion of the first side sill frame and the second side sill frame.

[0014] At least one of the first flat portion and the second flat portion may include concavo-convex portions.

[0015] The length of the side sill frame in the longitudinal direction of the first flat portion and the second flat portion can be any value between 40 mm and 70 mm inclusive.

[0016] The angle formed by the extension line of the first flat portion and the inclined portion and the angle formed by the extension line of the second flat portion and the inclined portion can be any value between 45° and 75° inclusive.

[0017] The unit section can include a third flat portion positioned parallel to the longitudinal direction of the side sill frame; a third inclined portion connected from the third flat portion and arranged to incline upward; and a fourth inclined portion connected from the third inclined portion and arranged to incline downward.

[0018] The unit section can include a fourth flat portion positioned parallel to the longitudinal direction of the side sill frame; a fifth inclined portion connected from the fourth flat portion and arranged to incline downward; and a sixth inclined portion connected from the fifth inclined portion and arranged to incline upward.

[0019] The unit section can include a seventh inclined portion arranged to incline upward; and an eighth inclined portion connected from the seventh inclined portion and arranged to incline downward.

[0020] The seventh inclined portion and the eighth inclined portion can have a flat plate shape.

[0021] The seventh inclined portion and the eighth inclined portion can have a curved plate shape.

[0022] The above unit interval includes a first unit interval disposed above in the height direction of the side sill frame; and a second unit interval disposed below the first unit interval. The first unit interval includes a fifth flat portion positioned parallel to the length direction of the side sill frame; a ninth inclined portion connected from the fifth flat portion and disposed inclined upward; and a tenth inclined portion connected from the ninth inclined portion and disposed inclined downward. The second unit interval can include a sixth flat portion positioned parallel to the length direction of the side sill frame; an eleventh inclined portion connected from the sixth flat portion and disposed inclined downward; and a twelfth inclined portion connected from the eleventh inclined portion and disposed inclined upward.

[0023] The fifth flat portion and the sixth flat portion can be arranged in contact with each other.

[0024] The above unit interval includes a first unit interval disposed above in the height direction; and a second unit interval disposed below the first unit interval. The first unit interval includes a seventh flat portion positioned parallel to the length direction of the side sill frame; a thirteenth inclined portion connected to the seventh flat portion and disposed inclined upward; an eighth flat portion existing at a position lower than the seventh flat portion and connected to the thirteenth inclined portion; and a fourteenth inclined portion connected to the eighth flat portion and disposed inclined downward. The second unit interval can include a ninth flat portion positioned parallel to the length direction of the side sill frame; a fifteenth inclined portion connected to the ninth flat portion and disposed inclined downward; a tenth flat portion existing at a position lower than the ninth flat portion and connected to the fifteenth inclined portion; and a sixteenth inclined portion connected to the tenth flat portion and disposed inclined upward.

[0025] The seventh flat portion and the ninth flat portion can be arranged in contact with each other.

[0026] The above unit interval includes a first unit interval arranged on the upper side in the height direction of the side sill frame; and a second unit interval arranged on the lower side of the first unit interval. The first unit interval includes a 17th inclined portion arranged to incline upward; and an 18th inclined portion connected to the 17th inclined portion and arranged to incline downward. The second unit interval can include a 19th inclined portion arranged to incline downward; and a 20th inclined portion connected to the 19th inclined portion and arranged to incline upward.

[0027] At least one of the side sill frame and the reinforcement frame can be made of steel.

[0028] The reinforcement frame can be made of a single steel plate.

[0029] The thickness of the reinforcement frame can be any value between 1.8 mm and 2.2 mm.

[0030] The reinforcement frame can have a tensile strength of 1180 MPa or more and a yield strength of any value between 850 MPa and 1060 MPa.

Advantages of the Invention

[0031] According to the present invention, the collision energy absorption efficiency of the side sill can be improved, and the side sill can be lightened.

[0032] According to the present invention, the rigidity of the side sill can be increased, and the manufacturing cost can be reduced.

Brief Description of the Drawings

[0033]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0034] To assist in understanding the description of the embodiments of the present invention, elements with the same reference numerals in the accompanying drawings are the same elements, and among the components that perform the same functions in each embodiment, related components are represented by the same or numbers on the extension line.

[0035] Note that, to clarify the gist of the present invention, descriptions of elements and techniques well known in the prior art are omitted, and hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

[0036] However, the idea of the present invention is not limited to the disclosed embodiments, and other forms with specific components added, changed, or deleted by those skilled in the art can also be proposed, which are still within the scope of the same idea of the present invention.

[0037] Hereinafter, the X-axis shown in the attached drawings is the width direction of the side sill, the Y-axis is the length direction of the side sill, and the Z-axis is the height direction of the side sill.

[0038] FIG. 1 is a perspective view of a vehicle side sill according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line I-I' of FIG. 1.

[0039] As shown in FIG. 1, a vehicle side sill 100 according to a first embodiment of the present invention may include a side sill frame 110 having a hollow portion 113 and a reinforcing frame 120 positioned in the hollow portion 113.

[0040] Both sides of the reinforcing frame 120 can be coupled to the side sill frame 110 and can continuously exist in a certain section in the Y-axis direction in the hollow portion 113 of the side sill frame 110.

[0041] The reinforcing frame 120 is continuous in the length direction of the side sill frame 110 and has unit sections with varying heights, and the upper and lower surfaces of the reinforcing frame 120 can be spaced apart from the side sill frame 110. This is to simultaneously achieve improved collision energy absorption efficiency and weight reduction.

[0042] Specifically, the reinforcing frame (120 in FIG. 1) can be spaced apart from the upper and lower surfaces of the first side sill frame (111 in FIG. 1) and the upper and lower surfaces of the second side sill frame (112 in FIG. 1), respectively.

[0043] According to such a reinforced frame, when an impact is applied to the side sill frame (110 in FIG. 1) in the X-axis direction (X in FIG. 1), the ability to absorb collision energy can be improved.

[0044] By arranging the reinforcing frame 120 so as to be separated from the upper and lower surfaces of the side sill frame 110 respectively, when an impact is applied in the X-axis direction or the like, the reinforcing frame 120 can be arranged in the central region in the Z-axis direction so that the maximum deformation load can be realized, and thereby there is an effect that the collision energy absorption efficiency can be improved while maximizing the weight reduction of the vehicle.

[0045] The above-mentioned reinforcing frame 120 can be present in a staggered pattern in the Y-axis direction in the above-mentioned hollow portion 113.

[0046] In the first embodiment of the present invention, the side sill frame may include a first side sill frame to which one side of the reinforcing frame 120 is joined and a second side sill frame to which the other side of the reinforcing frame is joined.

[0047] The first side sill frame and the second side sill frame can be joined to each other to form a joint portion 114.

[0048] FIG. 2 shows the cross-sectional shape in the length direction of the side sill frame of the reinforcing frame (120 in FIG. 1) according to the first embodiment of the present invention, that is, in the Y-axis direction.

[0049] The cross-sectional shape of the above-mentioned reinforcing frame may include a first flat portion 121a located parallel to the length direction of the side sill frame, an inclined portion 122 connected to the first flat portion 121a and arranged obliquely, and a second flat portion 121b connected to the inclined portion 122.

[0050] The second flat portion 121b can be located at a position lower than the first flat portion 121a in the Z-axis direction.

[0051] The first flat portion 121a and the second flat portion 121b can be provided in the hollow portion (113 in FIG. 1) so as to face the joint portion (114 in FIG. 1) of the first side sill frame (111 in FIG. 1) and the second side sill frame (112 in FIG. 1). Here, the meaning of facing means that the first flat portion 121a and the second flat portion 121b are arranged so as to face the joint portion 114.

[0052] The first flat portion 121a can be arranged so as to face the joint portion (114 in FIG. 1) of the first side sill frame (111 in FIG. 1) and the second side sill frame (112 in FIG. 1) arranged on the upper side. The second flat portion 121b can be arranged so as to face the joint portion (114 in FIG. 1) of the first side sill frame (111 in FIG. 1) and the second side sill frame (112 in FIG. 1) arranged on the lower side.

[0053] The joint portion 114 arranged on the upper side and the first flat portion 121a can be arranged separated from each other in a face-to-face state, and the joint portion 114 arranged on the lower side and the second flat portion 121b can be arranged separated from each other in a face-to-face state.

[0054] The first flat portion 121a and the second flat portion 121b can be positioned parallel to the Y-axis direction, and the inclined portion 122 can connect the first flat portion 121a and the second flat portion 121b.

[0055] The inclined portion 122 can include a first inclined portion 122a and a second inclined portion 122b. The first inclined portion 122a can be connected from the first flat portion 121a to the second flat portion 121b and be arranged to incline downward, and the second inclined portion 122b can be connected from the second flat portion 121b to the first flat portion 121a and be arranged to incline upward.

[0056] The above-described first flat portion 121a, the above-described second flat portion 121b, and the above-described inclined portion 122 can continuously exist in the Y-axis direction in the above-described hollow portion (113 in FIG. 1). The unit interval can be composed of a first flat portion 121a, a first inclined portion 122a, a second flat portion 121b, and a second inclined portion 122b. A plurality of unit intervals can be repeated in the Y-axis direction.

[0057] According to an embodiment of the present invention, the first flat portion 121a and the second flat portion 121b can have the same length in the Y-axis direction.

[0058] Further, according to the first embodiment of the present invention, the lengths of the first flat portion 121a and the second flat portion 121b in the Y-axis direction can be any one value between 40 mm and 70 mm.

[0059] When the lengths of the first flat portion 121a and the second flat portion 121b in the Y-axis direction are less than 40 mm, the period of the repeating pattern of the unit interval of the reinforcing frame 120 becomes short, so that the amount of the material used increases while the weight increases, which may have an adverse effect on weight reduction.

[0060] When the lengths of the first flat portion 121a and the second flat portion 121b in the Y-axis direction exceed 70 mm, a decrease in the resistance to deformation of the first flat portion 121a and the second flat portion 121b may occur, and since the period of the repeating pattern of the unit interval of the reinforcing frame 120 becomes long, a decrease in the performance of the collision energy absorption efficiency may occur due to a decrease in the resistance portion that resists deformation.

[0061] Further, according to the first embodiment of the present invention, the angle formed by the extension line of the second flat portion 121b and the inclined portion 122 can be any one value between 45° and 75°.

[0062] This can be similarly applied to the first flat portion 121a, and the angle θ formed by the extension line of the first flat portion 121a and the inclined portion 122 can also be any one value between 45° and 75°.

[0063] When the angle θ formed by the extension line of the second flat portion 121b and the inclined portion 122 is less than 45°, the period of the repeating pattern of the unit section of the reinforcing frame 120 becomes long, so there is a possibility that the performance of the collision energy absorption efficiency decreases due to the decrease in the resistance portion that resists deformation. This may also cause a decrease in the performance of the collision energy absorption efficiency when the angle θ formed by the extension line of the first flat portion 121a and the inclined portion 122 is less than 45°.

[0064] When the angle θ formed by the extension line of the second flat portion 121b and the inclined portion 122 exceeds 75°, the period of the repeating pattern of the unit section of the reinforcing frame 120 becomes short, so the weight increases while the amount of material used increases, which may have an adverse effect on weight reduction. This may also have an adverse effect on weight reduction when the angle θ formed by the extension line of the first flat portion 121a and the inclined portion 122 exceeds 75°.

[0065] On the other hand, the length of the inclined portion 122 in the Z-axis direction can be appropriately selected and applied according to the cross-sectional height of the seat cross member of the vehicle to which the vehicle side sill will be applied later and the mounting structure of the battery.

[0066] According to such a present invention, the collision energy absorption ability of the reinforcing frame with respect to its weight can be maximized.

[0067] FIG. 3 shows a cross section of a reinforcing frame (120 in FIG. 1) according to a second embodiment of the present invention. As shown in FIG. 3, at least one of the first flat portion 121a and the second flat portion 121b of the reinforcing frame according to another embodiment of the present invention can include uneven portions 130.

[0068] The uneven portion 130 can include a protruding portion 131 protruding in the direction in which the Z-axis increases and a recessed portion 132 formed in a concave shape with respect to the direction in which the Z-axis increases.

[0069] The above-mentioned protrusion 131 can be formed on the second flat portion 121b, and the recess 132 can be formed on the first flat portion 121a. However, this is not necessarily limited by the present invention. The protrusion 131 can also be formed on the first flat portion 121a, and the recess 132 can also be formed on the second flat portion 121b. Further, on the first flat portion 121a and the second flat portion 121b, the protrusion and the recess can exist simultaneously.

[0070] According to the above-mentioned protrusion 131 and the recess 132, the rigidity of the reinforcing frame (120 in FIG. 1) can be further increased.

[0071] The above-mentioned protrusion 131 and the recess 132 can be formed by bending and forming the above-mentioned reinforcing frame (120 in FIG. 1).

[0072] According to the above-mentioned protrusion 131 and the recess 132, the rigidity of the reinforcing frame can be increased without increasing the weight of the reinforcing frame (120 in FIG. 1).

[0073] On the other hand, FIG. 4 shows a cross-section of a normal vehicle side sill 10, and FIG. 5 shows a load-displacement diagram of the vehicle side sill in FIG. 4 (10 in FIG. 4) and the vehicle side sill in FIG. 1 (100 in FIG. 1).

[0074] In FIG. 5, the length of the first flat portion (121a in FIG. 2) of the reinforcing frame (120 in FIG. 1) of the vehicle side sill (100 in FIG. 1) according to the present invention is 50 mm, the length of the second flat portion (121b in FIG. 2) is 50 mm, the angle θ formed by the extension line of the second flat portion (121b in FIG. 2) and the inclined portion (122 in FIG. 2) and the angle θ formed by the extension line of the first flat portion (121a in FIG. 2) and the inclined portion (122 in FIG. 2) are 51.2°, and the thickness of the reinforcing frame (120 in FIG. 1) is applied at 2.0 mm.

[0075] In FIG. 5, the load-displacement value of the vehicle side sill (100 in FIG. 1) according to the present invention shown in FIG. 1 is indicated by a first value L1, and the load-displacement value of the vehicle side sill (10 in FIG. 4) shown in FIG. 4 is indicated by a second value L2.

[0076] Referring to the first value L1 and the second value L2, it can be seen that the displacement at the same load of the vehicle side sill (100 in FIG. 1) shown in FIG. 1 is relatively small compared to the normal vehicle side sill (10 in FIG. 4) shown in FIG. 4.

[0077] Also, referring to the fact that the cross-sectional structure of the vehicle side sill (100 in FIG. 1) according to the present invention is simpler than the cross-sectional structure of the normal vehicle side sill (10 in FIG. 4), and the number of components of the vehicle side sill (100 in FIG. 1) according to the present invention is less than the number of components of the normal vehicle side sill (10 in FIG. 4), it can be seen that the vehicle side sill of the present invention has significantly improved impact energy absorption ability compared to the normal vehicle side sill.

[0078] Also, according to the test result values, when the weight of the side sill frame (110 in FIG. 1) of the vehicle side sill (100 in FIG. 1) according to the present invention is 15.8 Kg, the impact energy absorption ability per unit weight (Internal Energy ratio per kg (KJ / kg)) is 82.9%. For the side sill frames (11, 12 in FIG. 4) of the normal vehicle side sill (10 in FIG. 4), when the weight is 22.1 Kg, the impact energy absorption ability per unit weight (Internal Energy ratio per kg (KJ / kg)) is 61.7%. Therefore, it can be seen that the vehicle side sill according to the present invention is lighter than the normal vehicle side sill but has significantly higher impact energy absorption ability.

[0079] According to the present invention as described above, while reducing the weight of the vehicle side sill, its impact energy absorption ability can be improved.

[0080] In addition, by arranging the reinforcing frame at an optimal position inside the side sill frame, it is possible to achieve the maximum impact energy absorption capacity with the minimum number of reinforcing frames and the minimum weight of the reinforcing frames.

[0081] Hereinafter, with reference to FIGS. 6 to 13, the vehicle side sill according to the third to tenth embodiments of the present invention will be described.

[0082] Here, the vehicle side sill according to the third to tenth embodiments of the present invention may be the same as the configuration of the vehicle side sill of the first embodiment (see FIGS. 1 and 2) described above, except that only the configuration of the reinforcing frame is partially different.

[0083] Therefore, it goes without saying that various embodiments of the components such as the side sill frame included in the above-described vehicle side sill can be applied to the third to tenth embodiments of the present invention.

[0084] FIG. 6 is a cross-sectional view showing the vehicle side sill according to the third embodiment of the present invention in the direction along the line I-I' of FIG. 1.

[0085] The unit section 120U of the third embodiment of the present invention may include a third flat portion 121c, a third inclined portion 122c, and a fourth inclined portion 122d. A plurality of unit sections 120U can be repeated in the Y-axis direction. The third flat portion 121c, the third inclined portion 122c, and the fourth inclined portion 122d can exist continuously in the Y-axis direction in the hollow portion 113.

[0086] The third flat portion 121c can be positioned parallel to the length direction of the side sill frame 110. The third inclined portion 122c is connected from the third flat portion 121c and can be arranged to incline upward. The fourth inclined portion 122d is connected from the third inclined portion 122c and can be arranged to incline downward. As an example, the third inclined portion 122c and the fourth inclined portion 122d can have the same length.

[0087] The length of the third flat portion 121c in the Y-axis direction can be any value between 40 mm and 70 mm. The effect thereof can be the same as the effect described in the first embodiment of the present invention above.

[0088] The angle θ formed by the extension line of the third flat portion 121c and the third inclined portion 122c can be any value between 45° and 75°. The angle θ formed by the extension line of the third flat portion 121c and the fourth inclined portion 122d can be any value between 45° and 75°. The effect thereof can be the same as the effect described in the first embodiment of the present invention above.

[0089] FIG. 7 is a cross-sectional view showing the vehicle side sill according to the fourth embodiment of the present invention in the direction along the line I-I' in FIG. 1.

[0090] The unit section 120U of the fourth embodiment of the present invention can include a fourth flat portion 121d, a fifth inclined portion 122e, and a sixth inclined portion 122f. A plurality of unit sections 120U can be repeated in the Y-axis direction. The fourth flat portion 121d, the fifth inclined portion 122e, and the sixth inclined portion 122f can continuously exist in the Y-axis direction in the hollow portion 113.

[0091] The fourth flat portion 121d can be positioned parallel to the longitudinal direction of the side sill frame 110. The fifth inclined portion 122e can be connected from the fourth flat portion 121d and arranged to incline downward. The sixth inclined portion 122f can be connected from the fifth inclined portion 122e and arranged to incline upward.

[0092] The length of the fourth flat portion 121d in the Y-axis direction can be any value between 40 mm and 70 mm. The effect thereof can be the same as the effect described in the first embodiment of the present invention above.

[0093] The angle θ formed by the extension line of the third flat portion 121c and the fifth inclined portion 122e can be any one value between 45° and 75°. The angle θ formed by the extension line of the fourth flat portion 121d and the sixth inclined portion 122f can be any one value between 45° and 75°. The effect thereof can be the same as the effect described in the first embodiment of the present invention above.

[0094] FIG. 8 is a cross-sectional view showing a vehicle side sill according to a fifth embodiment of the present invention in a direction along the line I-I' of FIG. 1, and FIG. 9 is a cross-sectional view showing a vehicle side sill according to a sixth embodiment of the present invention in a direction along the line I-I' of FIG. 1.

[0095] The unit section 120U of the fifth and sixth embodiments of the present invention can include a seventh inclined portion 122g and an eighth inclined portion 122h. The seventh inclined portion 122g can be arranged to incline upward. The eighth inclined portion 122h can be connected from the seventh inclined portion 122g and arranged to incline downward. As an example, the seventh inclined portion 122g and the eighth inclined portion 122h can have the same length.

[0096] Referring to FIG. 8, the seventh inclined portion 122g and the eighth inclined portion 122h can have a flat plate shape.

[0097] Referring to FIG. 9, the seventh inclined portion 122g and the eighth inclined portion 122h can have a curved plate shape.

[0098] FIG. 10 is a cross-sectional view showing a vehicle side sill according to a seventh embodiment of the present invention in a direction along the line I-I' of FIG. 1.

[0099] The unit section 120U of the seventh embodiment of the present invention can include a first unit section 120U-1 and a second unit section 120U-2. The first unit section 120U-1 can be arranged on the upper side in the height direction of the side sill frame 110, and the second unit section 120U-2 can be arranged on the lower side of the first unit section 120U-1.

[0100] The first unit section 120U-1 can include a fifth flat portion 121e, a ninth inclined portion 122i, and a tenth inclined portion 122j.

[0101] The fifth flat portion 121e can be positioned parallel to the longitudinal direction of the side sill frame 110. The ninth inclined portion 122i can be connected from the fifth flat portion 121e and arranged to incline upward. The tenth inclined portion 122j can be connected from the ninth inclined portion 122i and arranged to incline downward. As an example, the ninth inclined portion 122i and the tenth inclined portion 122j can have the same length.

[0102] The second unit section 120U-2 can include a sixth flat portion 121f, an eleventh inclined portion 122k, and a twelfth inclined portion 122l.

[0103] The sixth flat portion 121f can be positioned parallel to the longitudinal direction of the side sill frame 110. The eleventh inclined portion 122k can be connected from the sixth flat portion 121f and arranged to incline downward. The twelfth inclined portion 122l can be connected from the eleventh inclined portion 122k and arranged to incline upward. As an example, the eleventh inclined portion 122k and the twelfth inclined portion 122l can have the same length.

[0104] The fifth flat portion 121e and the sixth flat portion 121f can be arranged in contact with each other. As an example, the fifth flat portion 121e and the sixth flat portion 121f can be joined to each other by an adhesive or a welding method.

[0105] When an impact is applied in the X-axis direction or the like, deformation may occur in the first unit section 120U-1 and the second unit section 120U-2 of the reinforcement frame 120. At this time, by arranging the fifth flat portion 121e of the first unit section 120U-1 and the sixth flat portion 121f of the second unit section 120U-2 to be in contact with each other, the first unit section 120U-1 and the second unit section 120U-2 can correct each other's deformation, and the collision energy absorption efficiency of the vehicle side sill can be improved.

[0106] FIG. 11 is a cross-sectional view showing a vehicle side sill according to the eighth embodiment of the present invention in a direction along line I-I' of FIG. 1.

[0107] The unit section 120U of the eighth embodiment of the present invention can include a first unit section 120U-1 and a second unit section 120U-2. The first unit section 120U-1 can be arranged on the upper side in the height direction of the side sill frame 110, and the second unit section 120U-2 can be arranged on the lower side of the first unit section 120U-1.

[0108] The first unit section 120U-1 can include a seventh flat portion 121g, a thirteenth inclined portion 122m, an eighth flat portion 121h, and a fourteenth inclined portion 122n.

[0109] The seventh flat portion 121g can be positioned parallel to the length direction of the side sill frame 110. The thirteenth inclined portion 122m can be connected to the seventh flat portion 121g and arranged to incline upward. The eighth flat portion 121h can be connected to the thirteenth inclined portion 122m and exist at a position lower than the seventh flat portion 121g. The fourteenth inclined portion 122n can be connected to the eighth flat portion 121h and arranged to incline downward.

[0110] The seventh flat portion 121g and the eighth flat portion 121h can be positioned parallel to the Y-axis direction, and the seventh flat portion 121g can exist at a position lower than the eighth flat portion 121h in the Z-axis direction.

[0111] The second unit section 120U-2 can include a ninth flat portion 121i, a fifteenth inclined portion 122o, a tenth flat portion 121j, and a sixteenth inclined portion 122p.

[0112] The ninth flat portion 121i can be positioned parallel to the longitudinal direction of the side sill frame 110. The fifteenth inclined portion 122o can be connected to the ninth flat portion 121i and be disposed to incline downward. The tenth flat portion 121j can be connected to the fifteenth inclined portion 122o and exist at a position lower than that of the ninth flat portion 121i. The sixteenth inclined portion 122p can be connected to the tenth flat portion 121j and be disposed to incline upward.

[0113] The ninth flat portion 121i and the tenth flat portion 121j can be positioned parallel to the Y-axis direction, and the tenth flat portion 121j can exist at a position lower than that of the ninth flat portion 121i in the Z-axis direction.

[0114] The seventh flat portion 121g and the ninth flat portion 121i can be disposed in contact with each other. As an example, the seventh flat portion 121g and the ninth flat portion 121i can be joined to each other by an adhesive or a welding method.

[0115] When an impact is applied in the X-axis direction or the like, deformation may occur in the first unit section 120U-1 and the second unit section 120U-2 of the reinforcement frame 120. At this time, by disposing the seventh flat portion 121g of the first unit section 120U-1 and the ninth flat portion 121i of the second unit section 120U-2 in contact with each other, the first unit section 120U-1 and the second unit section 120U-2 can correct each other's deformation, and the collision energy absorption efficiency of the vehicle side sill can be improved.

[0116] FIG. 12 is a cross-sectional view showing a vehicle side sill according to a ninth embodiment of the present invention in a direction along the line I-I' in FIG. 1, and FIG. 13 is a cross-sectional view showing a vehicle side sill according to a tenth embodiment of the present invention in a direction along the line I-I' in FIG. 1.

[0117] The unit interval 120U of the ninth and tenth embodiments of the present invention can include a first unit interval 120U-1 and a second unit interval 120U-2. The first unit interval 120U-1 can be arranged on the upper side in the height direction of the side sill frame 110, and the second unit interval 120U-2 can be arranged on the lower side of the first unit interval 120U-1.

[0118] The first unit interval 120U-1 can include a seventeenth inclined portion 122q and an eighteenth inclined portion 122r. The seventeenth inclined portion 122q can be inclined upward. The eighteenth inclined portion 122r can be connected from the seventeenth inclined portion 122q and can be inclined downward. As an example, the seventeenth inclined portion 122q and the eighteenth inclined portion 122r can have the same length.

[0119] The second unit interval 120U-2 can include a nineteenth inclined portion 122s and a twentieth inclined portion 122t. The nineteenth inclined portion 122s can be inclined downward. The twentieth inclined portion 122t can be connected from the nineteenth inclined portion 122s and can be inclined upward. As an example, the nineteenth inclined portion 122s and the twentieth inclined portion 122t can have the same length.

[0120] Referring to FIG. 12, the seventeenth inclined portion 122q, the eighteenth inclined portion 122r, the nineteenth inclined portion 122s, and the twentieth inclined portion 122t can have a flat plate shape. Referring to FIG. 13, the seventeenth inclined portion 122q, the eighteenth inclined portion 122r, the nineteenth inclined portion 122s, and the twentieth inclined portion 122t can have a curved plate shape.

[0121] The lower intersection point where the seventeenth inclined portion 122q and the eighteenth inclined portion 122r of the first unit interval 120U-1 intersect, and the upper intersection point where the nineteenth inclined portion 122s and the twentieth inclined portion 122t of the second unit interval 120U-2 intersect can be arranged in contact with each other. The lower intersection point of the first unit interval 120U-1 and the upper intersection point of the second unit interval 120U-2 can be joined to each other by an adhesive or a welding method.

[0122] In the first to tenth embodiments of the present invention, at least one of the side sill frame 110 and the reinforcement frame 120 can be made of steel material. According to this, the mechanical strength of the vehicle side sill can be improved. Further, according to this, the collision energy absorption ability can be further improved compared to a vehicle side sill (not shown) made of aluminum of the same weight.

[0123] Therefore, it is possible to realize a vehicle side sill with improved collision energy absorption ability compared to a vehicle side sill made of aluminum while preventing an increase in the load of the entire vehicle on the vehicle side sill made of aluminum.

[0124] In the first to tenth embodiments of the present invention, the thickness of the reinforcement frame 120 can be any one value of 1.8 mm or more and 2.2 mm or less.

[0125] When the thickness of the reinforcement frame 120 is less than 1.8 mm, there is a possibility that the performance of the collision energy absorption efficiency may decrease due to a decrease in the resistance to deformation of the reinforcement frame 120. When the thickness of the reinforcement frame 120 exceeds 2.2 mm, there is a problem that the weight reduction effect is reduced due to an increase in the weight of the reinforcement frame 120.

[0126] In the first to tenth embodiments of the present invention, the reinforcement frame 120 can be made of a material including an ultra-high strength steel with a tensile strength of 980 MPa or more.

[0127] In the first to tenth embodiments of the present invention, the reinforcement frame 120 can be made of a material including 1180 TRIP steel.

[0128] In the first to tenth embodiments of the present invention, the first side sill frame 111 and the second side sill frame 112 can be made of a material including 1470 MART steel.

[0129] Also, in the first to tenth embodiments of the present invention, the reinforcing frame 120 can be formed by bending a single steel plate. According to this, the mechanical strength of the reinforcing frame 120 can be further improved, and it can contribute to the reduction of manufacturing cost.

[0130] Also, in the first to tenth embodiments of the present invention, the reinforcing frame 120 can have a tensile strength of 1180 MPa or more and a yield strength of any one value between 850 MPa and 1060 MPa.

[0131] When the vehicle side sill is formed of steel as described above, its collision energy absorption ability can be at least equal to or exceed that of a vehicle side sill made of aluminum of the same weight.

[0132] Therefore, it becomes possible to improve the collision energy absorption efficiency to be equal to or higher while reducing the weight of the side sill compared to when the side sill is produced from aluminum.

[0133] In the first to tenth embodiments of the present invention, one side of the reinforcing frame 120 can be arc welded to the first side sill frame 111. Further, the other side of the reinforcing frame 120 can be adhered to the second side sill frame 112 with an adhesive. According to this, the convenience of the manufacturing work of the vehicle side sill can be improved.

[0134] According to the vehicle side sill of the present invention as described above, when a load is applied in the X-axis direction, it can be facilitated for the vehicle side sill to be compressed and deformed in the X-axis direction, and the impact absorption ability can be improved. Therefore, it is possible to minimize the transmission of impact to the space (not shown) where the vehicle battery is present and the space where passengers are present.

[0135] The matters described above are for one embodiment of the present invention. However, the scope of the rights of the present invention is not limited thereto, and it is obvious to those having ordinary knowledge in the art that various modifications and variations are possible within the scope not departing from the technical idea of the present invention described in the claims.

Explanation of Reference Numerals

[0136] 110 Side sill frame 111 First side sill frame 112 Second side sill frame 113 Hollow portion 114 Joint portion 120 Reinforcement frame 120U Unit section 120U-1 First unit section 120U-2 Second unit section 121a First flat portion 121b Second flat portion 121c Third flat portion 121d Fourth flat portion 121e Fifth flat portion 121f Sixth flat portion 121g Seventh flat portion 121h Eighth flat portion 121i Ninth flat portion 121j Tenth flat portion 122 Inclined portion 122a First inclined portion 122b Second inclined portion 122c Third inclined portion 122d Fourth inclined portion 122e Fifth inclined portion 122f Sixth inclined portion 122g Seventh inclined portion 122h Eighth inclined portion 122i Ninth inclined portion 122j Tenth inclined portion 122k Eleventh inclined portion 122l Twelfth inclined portion 122m Thirteenth inclined portion 122n Fourteenth inclined portion 122o Fifteenth inclined portion 122p Sixteenth inclined portion 122q Seventeenth inclined portion 122r Eighteenth inclined portion 122s Nineteenth inclined portion 122t Twentieth inclined portion 130 Concavo-convex portion 131 Protruding portion 132 Concave portion

[0137] [Clause 1] A side sill frame including a hollow portion; and A reinforcing frame disposed in the length direction of the side sill frame inside the hollow portion; The reinforcing frame is Continuous in the length direction of the side sill frame, having unit intervals with varying heights, and with the upper and lower surfaces spaced apart from the side sill frame, a vehicle side sill. [Clause 2] The unit interval is A first flat portion positioned parallel to the length direction of the side sill frame; An inclined portion connected to the first flat portion and disposed obliquely; and A second flat portion connected to the inclined portion and existing at a position lower than the first flat portion; The vehicle side sill according to clause 1. [Clause 3] The inclined portion is A first inclined portion connected from the first flat portion to the second flat portion and disposed obliquely downward; and A second inclined portion connected from the second flat portion to the first flat portion and disposed obliquely upward; The vehicle side sill according to clause 2. [Clause 4] The side sill frame is A first side sill frame to which one side of the reinforcing frame is joined; and A second side sill frame to which the other side of the reinforcing frame is joined and joined to the first side sill frame; The vehicle side sill according to clause 2, wherein The first flat portion and the second flat portion are Disposed to face the joint portion of the first side sill frame and the second side sill frame. [Clause 5] At least one of the first flat portion and the second flat portion is Including concavo-convex portions, the vehicle side sill according to clause 4. [Clause 6] The length of the side sill frame in the longitudinal direction of the first flat portion and the second flat portion is any one value of 40 mm or more and 70 mm or less, and the vehicle side sill according to any one of clauses 2 to 5. [Clause 7] The angle formed by the extension line of the first flat portion and the inclined portion and the angle formed by the extension line of the second flat portion and the inclined portion are any one value of 45° or more and 75° or less, and the vehicle side sill according to any one of clauses 2 to 5. [Clause 8] The unit interval is A third flat portion located parallel to the longitudinal direction of the side sill frame; A third inclined portion connected from the third flat portion and arranged to incline upward; and A fourth inclined portion connected from the third inclined portion and arranged to incline downward; and the vehicle side sill according to clause 1. [Clause 9] The unit interval is A fourth flat portion located parallel to the longitudinal direction of the side sill frame; A fifth inclined portion connected from the fourth flat portion and arranged to incline downward; and A sixth inclined portion connected from the fifth inclined portion and arranged to incline upward; and the vehicle side sill according to clause 1. [Clause 10] The unit interval is A seventh inclined portion arranged to incline upward; and An eighth inclined portion connected from the seventh inclined portion and arranged to incline downward; and the vehicle side sill according to clause 1. [Clause 11] The seventh inclined portion and the eighth inclined portion have a flat plate shape, and the vehicle side sill according to clause 10. [Clause 12] The seventh inclined portion and the eighth inclined portion have a curved plate shape, and the vehicle side sill according to clause 10. [Clause 13] The unit interval is A first unit interval arranged on the upper side in the height direction of the side sill frame; and a second unit section disposed below the first unit section; The first unit section includes a fifth flat section positioned parallel to the longitudinal direction of the side sill frame; a ninth inclined section connected to the fifth flat section and disposed obliquely upward; and a tenth inclined section connected to the ninth inclined section and disposed obliquely downward. The second unit section includes a sixth flat section positioned parallel to the longitudinal direction of the side sill frame; an eleventh inclined section connected to the sixth flat section and disposed obliquely downward; and a twelfth inclined section connected to the eleventh inclined section and disposed obliquely upward. The side sill for a vehicle according to claim 1. [Claim 14] The side sill for a vehicle according to claim 13, wherein the fifth flat section and the sixth flat section are disposed in contact with each other. [Claim 15] The unit section includes a first unit section disposed above in the height direction; and a second unit section disposed below the first unit section. The first unit section includes a seventh flat section positioned parallel to the longitudinal direction of the side sill frame; a thirteenth inclined section connected to the seventh flat section and disposed obliquely upward; an eighth flat section existing at a position lower than the seventh flat section and connected to the thirteenth inclined section; and a fourteenth inclined section connected to the eighth flat section and disposed obliquely downward. The second unit section includes a ninth flat section positioned parallel to the longitudinal direction of the side sill frame; a fifteenth inclined section connected to the ninth flat section and disposed obliquely downward; a tenth flat section existing at a position lower than the ninth flat section and connected to the fifteenth inclined section; and The vehicle side sill according to claim 1, including a 16th inclined portion that is connected to the 10th flat portion and is arranged to be inclined upward. [Article 16] The vehicle side sill according to claim 15, wherein the 7th flat portion and the 9th flat portion are arranged in contact with each other. [Article 17] The unit interval is a 1st unit interval arranged above in the height direction of the side sill frame; and a 2nd unit interval arranged below the 1st unit interval; and includes The 1st unit interval is a 17th inclined portion arranged to be inclined upward; and an 18th inclined portion that is connected from the 17th inclined portion and is arranged to be inclined downward; and includes The 2nd unit interval is a 19th inclined portion arranged to be inclined downward; and a 20th inclined portion that is connected from the 19th inclined portion and is arranged to be inclined upward; and includes the vehicle side sill according to claim 1. [Article 18] The vehicle side sill according to any one of claims 1 to 5 and 8 to 16, wherein at least one of the side sill frame and the reinforcement frame is made of steel. [Article 19] The reinforcement frame is made of a single steel plate, and is the vehicle side sill according to any one of claims 1 to 5 and 8 to 17. [Article 20] The vehicle side sill according to any one of claims 1 to 5 and 8 to 17, wherein the thickness of the reinforcement frame is any value from 1.8 mm or more to 2.2 mm or less. [Article 21] The reinforcement frame is The vehicle side sill according to any one of claims 1 to 5 and 8 to 17, which has a tensile strength of 1180 MPa or more and a yield strength of any value from 850 MPa or more to 1060 MPa or less.

Claims

1. A side sill frame including a hollow portion; and A reinforcing frame disposed in the length direction of the side sill frame inside the hollow portion; including, The reinforcing frame is Continuous in the length direction of the side sill frame, having a unit section with a varying height, the upper and lower surfaces being spaced apart from the side sill frame, The unit section is A first flat portion extending along the length direction of the side sill frame; A second flat portion existing at a position lower than the first flat portion; A first inclined portion connecting from the first flat portion to the second flat portion and disposed inclined downward; and A second inclined portion connecting from the second flat portion to the first flat portion and disposed inclined upward; including, The side sill frame is A first side sill frame to which one side of the reinforcing frame is joined; and A second side sill frame to which the other side of the reinforcing frame is joined and joined to the first side sill frame; including, The first flat portion and the second flat portion are Disposed such that the joint between the first side sill frame and the second side sill frame faces each other, The joint disposed on the upper side and the first flat portion are spaced apart from each other in a facing state, The joint disposed on the lower side and the second flat portion are spaced apart from each other in a facing state, a vehicle side sill.

2. At least one of the first flat portion and the second flat portion is Including concavo-convex portions, the vehicle side sill according to claim 1.

3. The length of the first flat portion and the second flat portion in the length direction of the side sill frame is any one value between 40 mm and 70 mm, the vehicle side sill according to claim 2.

4. The angle formed by the extension line of the first flat portion and the first inclined portion and the angle formed by the extension line of the second flat portion and the second inclined portion are any one value between 45° and 75°, the vehicle side sill according to claim 2.

5. A side sill frame including a hollow portion; and A reinforcing frame disposed in the length direction of the side sill frame inside the hollow portion; including, The reinforcing frame is Continuous in the length direction of the side sill frame, having a unit section with a varying height, the upper and lower surfaces being spaced apart from the side sill frame, The unit section is A third flat portion extending along the length direction of the side sill frame; A third inclined portion connecting from the third flat portion and disposed inclined upward; and A fourth inclined portion that is connected to the third inclined portion and is inclined downward; and The side sill frame is A first side sill frame to which one side of the reinforcing frame is joined; and A second side sill frame to which the other side of the reinforcing frame is joined and which is joined to the first side sill frame; and The third flat portion is Arranged such that the joint between the first side sill frame and the second side sill frame faces each other, A vehicle side sill in which the joint portion disposed on the lower side and the third flat portion are spaced apart from each other while facing each other. **Claim 6** A side sill frame including a hollow portion; and A reinforcing frame disposed in the length direction of the side sill frame inside the hollow portion; and The reinforcing frame is Continuous in the length direction of the side sill frame, has a unit section in which the height changes, and the upper and lower surfaces are spaced apart from the side sill frame, The unit section is A fourth flat portion extending along the length direction of the side sill frame; A fifth inclined portion that is connected to the fourth flat portion and is inclined downward; and A sixth inclined portion that is connected to the fifth inclined portion and is inclined upward; and The side sill frame is A first side sill frame to which one side of the reinforcing frame is joined; and A second side sill frame to which the other side of the reinforcing frame is joined and which is joined to the first side sill frame; and The fourth flat portion is Arranged such that the joint between the first side sill frame and the second side sill frame faces each other, A vehicle side sill in which the joint portion disposed on the upper side and the fourth flat portion are spaced apart from each other while facing each other. **Claim 7** A side sill frame including a hollow portion; and A reinforcing frame disposed in the length direction of the side sill frame inside the hollow portion; and The reinforcing frame is Continuous in the length direction of the side sill frame, has a unit section in which the height changes, and the upper and lower surfaces are spaced apart from the side sill frame, The unit section is A first unit section disposed on the upper side in the height direction; and A second unit section disposed below the first unit section; and The first unit section is A seventh flat portion extending along the length direction of the side sill frame; A thirteenth inclined portion that is connected to the seventh flat portion and is inclined upward; An eighth flat portion that is connected to the thirteenth inclined portion and exists at a position lower than the seventh flat portion; and a fourteenth inclined portion that is connected to the eighth flat portion and is disposed to incline downward; the second unit interval a ninth flat portion that extends parallel to the longitudinal direction of the side sill frame; a fifteenth inclined portion that is connected to the ninth flat portion and is disposed to incline downward; a tenth flat portion that is connected to the fifteenth inclined portion and exists at a position lower than the ninth flat portion; and a sixteenth inclined portion that is connected to the tenth flat portion and is disposed to incline upward; the side sill frame a first side sill frame to which one side of the reinforcing frame is joined; and a second side sill frame to which the other side of the reinforcing frame is joined and which is joined to the first side sill frame; the eighth flat portion and the tenth flat portion are disposed such that the joint portion between the first side sill frame and the second side sill frame faces each other, the joint portion disposed on the upper side and the eighth flat portion are spaced apart from each other in a face-to-face state, a vehicle side sill in which the joint portion disposed on the lower side and the tenth flat portion are spaced apart from each other in a face-to-face state. **Claim 8** The vehicle side sill according to claim 7, wherein the seventh flat portion and the ninth flat portion are disposed in contact with each other. **Claim 9** The vehicle side sill according to any one of claims 1, 2, 5 to 8, wherein at least one of the side sill frame and the reinforcing frame is made of a steel material. **Claim 10** The reinforcing frame is made of a single steel plate, and is the vehicle side sill according to any one of claims 1, 2, 5 to 8. **Claim 11** The vehicle side sill according to any one of claims 1, 2, 5 to 8, wherein the thickness of the reinforcing frame is any value of 1.8 mm or more and 2.2 mm or less. **Claim 12** The reinforcing frame has a tensile strength of 1180 MPa or more and a yield strength of any value of 850 MPa or more and 1060 MPa or less, and is the vehicle side sill according to any one of claims 1, 2, 5 to 8.

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